Scope 3 emissions under UK SRS

What Scope 3 is

Scope 3 emissions are indirect greenhouse gas emissions across an entity's value chain — emissions not from the entity's own operations or purchased energy, but from activities upstream (suppliers, raw materials, transportation in) and downstream (products in use, end-of-life, investments) of the entity under S2 climate standard.

The GHG Protocol Corporate Value Chain (Scope 3) Standard3 defines Scope 3 across 15 categories — eight upstream (categories 1-8) and seven downstream (categories 9-15). The standard provides measurement methodology, accounting principles, and reporting guidance for each category.

For most large corporates, Scope 3 represents 60-90% of total emissions when measured comprehensively11. Manufacturing companies typically see purchased goods (category 1) as dominant; financial institutions see investments (category 15); oil and gas companies see use of sold products (category 11); retailers see categories 1 and 11 combined3.

UK SRS Scope 3 requirements

UK SRS S2 paragraph 29(a)1 requires disclosure of absolute gross greenhouse gas emissions for the reporting period in metric tonnes of CO2 equivalent, classified by Scope 1, Scope 2, and Scope 31. The seven Kyoto Protocol greenhouse gases must be aggregated using global warming potentials based on a 100-year time horizon from the latest IPCC assessment9.

For Scope 3 specifically, SRS S2 paragraph B321 requires categorisation across the 15 categories of the GHG Protocol Corporate Value Chain Standard3. Paragraph B331 requires the entity to disclose which categories are included in its measure — partial coverage is permitted, but the entity must be explicit about scope for compliance requirements.

Measurement must follow the GHG Protocol Corporate Standard (2004)4 for Scope 1 and Scope 2, and the GHG Protocol Corporate Value Chain Standard3 for Scope 3, unless the entity is required to use a different method by a jurisdictional authority or exchange1.

The 15 GHG Protocol categories

The 15 categories split into upstream (suppliers, inputs, internal operations excluding direct emissions) and downstream (customers, sold products, investments).

Upstream categories (1–8)

The upstream categories cover emissions from the entity's supply chain and indirect inputs:

• Category 1 — Purchased goods and services: emissions from the production of goods and services purchased by the entity. Typically dominant for manufacturers, retailers, and most non-financial corporates.
• Category 2 — Capital goods: emissions from production of long-lived capital assets (plant, equipment, vehicles) used by the entity.
• Category 3 — Fuel and energy-related activities: upstream emissions from extraction, production, and transport of fuels not in Scope 1 or 2 (e.g. well-to-tank emissions of purchased fuel).
• Category 4 — Upstream transportation and distribution: emissions from third-party transport of goods to the entity.
• Category 5 — Waste generated in operations: emissions from waste disposal and treatment.
• Category 6 — Business travel: emissions from employee travel for business.
• Category 7 — Employee commuting: emissions from employee commuting to and from work.
• Category 8 — Upstream leased assets: emissions from assets leased by the entity (where not in Scope 1 or 2).

Downstream categories (9–15)

The downstream categories cover emissions from products and services after they leave the entity's control:

• Category 9 — Downstream transportation and distribution: emissions from transport of sold products to end customers.
• Category 10 — Processing of sold products: emissions from further processing of intermediate products before final use.
• Category 11 — Use of sold products: emissions during the operational lifetime of products sold by the entity. Typically dominant for oil and gas, automotive, energy equipment, and consumer electronics.
• Category 12 — End-of-life treatment of sold products: emissions from disposal or recycling of sold products.
• Category 13 — Downstream leased assets: emissions from assets leased to other entities.
• Category 14 — Franchises: emissions from franchisee operations.
• Category 15 — Investments: emissions from investments, including financed emissions for financial institutions.

Transition reliefs

S2 requirements1 includes a first-year transition relief allowing entities to omit Scope 3 disclosure (including financed emissions) in the first annual reporting period of mandatory application.

The relief applies to the climate strategy disclosure as a whole — entities need not provide Scope 3 detail in their first UK SRS S2 cycle. This operates alongside existing Companies Act 2006 section 414CB requirements6.

FCA CP26/52 adds an optional additional one-year deferral on Scope 3 over and above the first-year implementation timeline in the standard itself2. The intent is to provide more time for Scope 3 data infrastructure to be built, particularly the supplier engagement workstream which typically takes 12-18 months.

The practical effect of these combined reliefs: for in-scope companies with December year-ends, Scope 3 becomes required on a comply-or-explain basis from accounting periods beginning reporting deadline for 20282 — the second year of mandatory climate-related disclosures application. First mandatory Scope 3 reports therefore publish in spring 2029.

Comply-or-explain from 2028

Under FCA CP26/5 paragraph 8.142, Scope 3 disclosure operates on a comply-or-explain basis from accounting periods beginning compliance timeline in 2028. Companies must either disclose Scope 3 emissions across material categories or explain specific constraints preventing disclosure for UK SRS compliance.

What counts as an adequate explanation matters here. A general statement that the company has not collected Scope 3 data is not sufficient — explanations must be substantive and specific to the disclosure being deferred2.

Acceptable explanations typically address:

• Data availability — specific gaps in supplier emissions data, with steps being taken to address them
• Commercial sensitivity — categories where disclosure would harm competitive position, with rationale
• Methodology limitations — categories where established measurement approaches don't fit the entity's operations
• Resource and timeline constraints — combined with a stated plan for progressive improvement

The FCA2 expects progressive enhancement of Scope 3 disclosure quality over time. Comply-or-explain is not a long-term escape — it's a mechanism for managing the transition from partial to comprehensive Scope 3 reporting while the underlying data infrastructure matures.

The FRC guidance10 emphasises that voluntary early adoption can provide competitive advantage during the transition period.

Category materiality assessment

UK SRS S21 does not require disclosure of every category for every entity. The entity must disclose which categories are included in its measure (paragraph B331), and the categories selected should reflect materiality — both quantitative (emissions magnitude relative to total Scope 3) and qualitative (stakeholder concerns, influence potential, risk factors).

The GHG Protocol Corporate Value Chain Standard3 identifies three relevance criteria for categories: significance to total Scope 3 emissions, relevance to business goals and stakeholder needs, and data availability and quality. The standard recommends entities identify categories that are likely to be material before investing in detailed measurement.

In practice, most large corporates identify three to five categories that account for the majority of their Scope 3 footprint11.

The remaining categories may be measured at lower precision (spend-based or industry-average) or omitted with explanation3. The expectation is that material categories receive primary-data treatment; non-material categories may use proxies1.

Measurement methodology

Scope 3 measurement follows the GHG Protocol Corporate Value Chain Standard3. The standard sets out three methodological approaches per category, varying by data availability and accuracy:

Activity-data approach (highest accuracy)

Uses primary activity data (e.g. supplier-reported emissions, fuel consumption records, mileage logs) multiplied by emission factors. Highest accuracy but requires supplier cooperation and verified data3.

Hybrid approach

Combines activity data for material flows with secondary data (industry averages, modelled emissions) for less material flows. Pragmatic balance between accuracy and feasibility for most large corporates3.

Spend-based approach

Uses financial spend with suppliers multiplied by sector-average emissions per unit of spend. Lowest accuracy but provides baseline coverage when supplier-specific data isn't available.

Typically used for categories 1 and 2 in early-stage reporting3.

UK SRS S2 paragraph B331 requires entities to disclose the methodology used per category, allowing readers to understand data quality and comparability. Where multiple methods are combined within a category (hybrid approach), the entity should explain the split.

Category 15 — Investments (financial institutions)

Category 15 covers emissions from investments — both equity investments and debt investments. For most non-financial entities, Category 15 is small or zero.

For financial institutions (asset managers, commercial banks, insurers), Category 15 is typically the dominant Scope 3 category and is treated separately in UK SRS S2 paragraphs B59-B661.

The standard imposes detailed financed emissions disclosure requirements on financial institutions1:

• Asset management — absolute gross financed emissions disaggregated by Scope 1, 2, and 3; total AUM included; percentage of AUM in scope; methodology and allocation method.
• Commercial banking — absolute gross financed emissions for each industry by asset class; gross exposure to each industry; percentage included; methodology.
• Insurance — absolute gross financed emissions by industry by asset class; gross exposure; percentage included; methodology.

UK SRS S2 paragraph B59A1 — a UK-specific addition not present in IFRS S25 — allows financial institutions to disclose financed emissions for a reporting period different from the financial statements where alignment is impracticable, provided the entity discloses the reasons, the measurement approach, and the timeline for alignment.

For methodology, financial institutions typically reference the PCAF Global GHG Accounting and Reporting Standard for the Financial Industry8 — though UK SRS does not mandate PCAF specifically. Industry classification choices materially affect disclosed figures.

Sector patterns

Different sectors face distinct Scope 3 profiles reflecting value chain characteristics and material category relevance. The dominant category typically accounts for 50%+ of total Scope 3, with two to three additional categories making up most of the remainder.

Sector-specific guidance is available through industry initiatives (e.g. CDP industry questionnaires11), and the GHG Protocol provides sector-specific calculation guidance for several industries within the Corporate Value Chain Standard3.

Data collection in practice

Production-quality Scope 3 reporting requires three distinct workstreams running in parallel.

Supplier engagement (12–18 months)

For Category 1 (purchased goods and services) — typically the largest Scope 3 component for non-financial entities — meaningful primary-data reporting requires direct engagement with suppliers.

This involves identifying material suppliers (typically the top 50-100 by spend), requesting emissions data, supporting suppliers without measurement capability, and verifying received data. The 12-18 month timeline reflects the supplier capacity-building element, not just the data request itself.

Data infrastructure (parallel)

Scope 3 data systems must handle multiple data types (activity, financial, emissions factors), multiple sources (supplier portals, ERP systems, travel platforms), and multiple measurement methods within categories3.

Most companies build dedicated Scope 3 platforms or extend existing carbon accounting systems11. Integration with financial systems is essential for the connectivity principle under UK SRS S11.

Methodology and assumptions (ongoing)

Each material category requires methodology selection, emissions factor sourcing, allocation method documentation, and assumption tracking3. UK SRS S21 requires entities to disclose methodology per category — the rationale must be defensible, especially under assurance review7.

Assurance under ISSA (UK) 5000

The FRC published ISSA (UK) 50007 as the UK sustainability assurance standard on 12 November 20257, effective 15 December 20267. Scope 3 disclosures fall within the scope of the standard where the entity obtains assurance.

Scope 3 presents particular assurance challenges given data availability and verification constraints. Assurance providers under ISSA (UK) 5000 typically focus on methodology appropriateness, data quality processes, and comply-or-explain justifications rather than precise emissions verification.

Limited assurance is the standard initial expectation; reasonable assurance is achievable for mature programmes with primary-data dominance.

The FCA2 does not propose to mandate Scope 3 assurance at this stage. Where companies obtain assurance voluntarily, they must disclose the assurance level, the standard used, and the provider.

Frequently asked questions